Yasushi Kawano
University of Texas Southwestern Medical Center
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Featured researches published by Yasushi Kawano.
Clinical and Experimental Medicine | 2003
F. Kawasaki; Yasushi Kawano; Z. Kosay Hasan; Hisashi Narahara; Isao Miyakawa
Abstract. In order to investigate the role of interleukin-6 (IL-6) and interleukin-6 soluble receptor (sR) in human ovulation, we evaluated the concentrations in human follicular fluid and analyzed the correlation of IL-6 and IL-6 sR with oocyte maturation. The oocytes were obtained from the follicular fluid of 45 women undergoing in vitro fertilization and embryo transfer. The concentrations of IL-6 and IL-6 sR in follicular fluid were measured by ELISA. In addition, granulosa cells obtained from the follicular fluid were cultured and treated with forskolin and 12-o-tetradecanoylphorbol 13-acetate for 24–48 h. The concentration of IL-6 was significantly higher in the follicular fluid than in the serum (P<0.01). In contrast, the concentration of IL-6 sR was significantly lower in the follicular fluid than in the serum (P<0.001). The concentrations of IL-6 and IL-6 sR were significantly higher in the follicular fluid containing mature oocytes than in fluid containing immature oocytes (P<0.05). The production of IL-6 was markedly increased over the basal level after 24 h of treatment with forskolin(P<0.001) and 48 h of treatment (P<0.01) with cultured granulosa cells. Our data suggest that IL-6 and IL-6 sR may play an important role in follicular growth and development in human preovulatory processes. It is possible that IL-6 in particular may be regulated by cAMP. IL-6 and IL-6 sR might also be valuable biochemical markers in the evaluation of oocyte maturation.
Clinical and Experimental Medicine | 2002
Yasushi Kawano; Satomi Nakamura; Kaei Nasu; Hisashi Narahara; Isao Miyakawa
Abstract Endometrial stromal cells undergo morphological and functional changes to facilitate oocyte implantation under regulation of various hormones and growth factors. We studied physiological induction by epidermal growth factor (EGF) of vascular endothelial growth factor (VEGF) in these cells. In human endometrial stromal cells, the effect of EGF, genistein, tryphostin AG1478 (a tyrosine kinase inhibitor), and wortmannin (a phosphatidylinositol 3-kinase inhibitor) on production of VEGF was examined: Total RNA was extracted and VEGF mRNA expression was quantified by Northern analysis. EGF induced production of VEGF by stromal cells in a time-dependent manner; the effect became significant after 12 h and increased further between 24 and 48 h (P<0.05). Dose dependency was also significant (P<0.01). Genistein, tryphostin AG1478, and wortmannin partially suppressed the increase in production induced by EGF (P<0.01, P< 0.01, P<0.01), respectively. Production of EGF by fertilized oocytes and trophoblasts has been reported in early pregnancy. VEGF is believed to be induced by EGF through mechanisms involving tyrosine kinase and phosphatidylinositol 3-kinase. The increase in VEGF may contribute to neovascularization that promotes proliferation of endometrium and placentation.
Fertility and Sterility | 1995
Hisashi Narahara; Yuichiro Tanaka; Yasushi Kawano; Karima Gholbzouri; Isao Miyakawa
OBJECTIVEnTo examine the role of platelet-activating factor (PAF) metabolism in the periovulatory processes.nnnDESIGNnThe PAF-acetylhydrolase activity in the follicular fluid (FF) obtained in conjunction with IVF-ET procedure was assayed and its activity was related to oocyte maturation. The PAF-acetylhydrolase activity also was related to the concentration of various ovarian hormones.nnnSETTINGnAll patients were managed and treated at Oita Medical University Hospital, Oita, Japan.nnnPATIENTSnThe study concerned 30 women between 28 and 36 years of age with tubal infertility.nnnMAIN OUTCOME MEASUREnThe activity of PAF-acetylhydrolase in FF was assayed as well as E2 and P. Oocyte maturation also was evaluated.nnnRESULTSnPlatelet-activating factor-acetylhydrolase activity was decreased significantly in the FFs of patients with a successful outcome of their pregnancies compared with the nonsuccessful group. Estradiol levels were negatively correlated with PAF-acetylhydrolase activities in the FFs. No correlation was found between the PAF-acetylhydrolase activity and P concentration in the FF. Significantly more mature and less immature oocytes were recovered in the group who subsequently became pregnant compared with the nonpregnant group.nnnCONCLUSIONSnIt is suggested that the decrease in PAF-acetylhydrolase activity may result in an increase of PAF in the FFs, which in turn may contribute to a successful pregnancy. The determination of PAF-acetylhydrolase activity in FF may serve as a prognostic marker for the evaluation of oocytes that are utilized in IVF-ET procedure.
American Journal of Obstetrics and Gynecology | 2003
Hisashi Narahara; Shinichiro Mine; Yasushi Kawano; Isao Miyakawa
日本産科婦人科學會雜誌 | 2015
Yui Itonaga; Masakazu Nishida; Yasushi Kawano; Akitoshi Yuge; Hisashi Narahara
日本産科婦人科學會雜誌 | 2014
Yasushi Kawano; Yufuko Kai; Akitoshi Yuge; Mitsutake Yano; Satoko Yamashita; Kaei Nasu; Hisashi Narahara
日本産科婦人科學會雜誌 | 2013
Yasushi Kawano; Yufuko Utsunomiya; Akitoshi Yuge; Naoko Kira; Mamiko Okamoto; Kaei Nasu; Hisashi Narahara
日本産科婦人科學會雜誌 | 2013
Tomoko Hirakawa; Yasushi Kawano; Masakazu Nishida; Akitoshi Yuge; Mitsutake Yano; Hisashi Narahara
日本産科婦人科學會雜誌 | 2012
Yasushi Kawano; Yufuko Utsunomiya; Hatsumi Tsusue; Yuko Miyamoto; Hisashi Narahara
日本産科婦人科學會雜誌 | 2011
Yasushi Kawano; Sinya Karakida; Tomoko Hirakawa; Yufuko Utsunomiya; Mamiko Okamoto; Naomi Inoue; Hisashi Narahara